IMR4350 and the 260 Remington

I was wondering if any of you had expirimented with this combo?
I have a Savage Predator max1 24" and with 40gr @2.8" I am accurate below 1/2" but only puching 2560fps. I went to 42 and I am pushing 2700 but they spread to over an inch. I see in my Lee paperwork they list 43.5 as max. I plan on pushing it up and trying some 43, and 43.5 to see if I can close them up with a little more velocity.
Anyone got a load in this rifle that shoots? I have been spoiled with my LRP 6.5CM and the 260 is being a little more particular! I am trying to use the same powder and 140gr Amaxes. That may be my issue!

I shoot 40.5g imr4350 under a 142g smk in lapua brass with a cci 200 to light it off. My barrel is 28" and im in the mid 2700s...I stopped at 40.5g for 2 reason first and foremost with this combo its like a laser and second its slightly compressed..I know several guys that shoot 140s and both H & IMR4350 that are above book max but if and when you get close watch for pressure signs and dont make big jumps. Youll find another node higher up.

My best loads with 140 amax and h4350 were 40.5 and 43.1. No pressure signs

My 260 experience with imr4350 was that it worked well but nothing special.
When I found H4350 I stopped looking.

I have alot of IMR4350. I use it for my 6.5CM. I happened upon this 260 in a trade and I like the rifle. I am just using it for my hunting rig, but I like accuracy! 1" is ok but I like 1/2" as my standard! Did I mention I had alot of IMR4350? I will find the sweet spot in a while. The accuracy @ 40 gr was 1/4", but 2560 is a bit slow! Thanks guys.

I tried some at 43 and 43.5 and 44 this afternoon. The accuracy is still not like the 40 gr but a little better. My chrono crapped out on me, it always does on a cloudy day, so I dont know the speed, but I had no pressure issues. I cant tell any difference in them from the 40 gr. I may load a few 44.5 tonight and try them tomorrow. Are 1/2 grain steps too large?

I always go up in 1% or so increments, works well for me.
Then when I see the results I hone in with smaller increments on what I like.
It's like cheap booze for prospective ladies then the good stuff to seal the deal.
1/2 grain is close enough to 1% for me.

IMHO .5G up are fine but thats just me and at 44.5 you getting close to what I know guys are shooting...im getting ready to run my loads up to that and past with a 142g bullet...but im not normal so be careful past 44g.

Appreciate it guys. I think with the 44.5 I will be at the velocity I am looking for and I hope she closes up a little. Man that group at 40 grains just spoiled me! I had a flier and still was well under a 1/2". Three were basically one hole. Without that flier It was about a 1/4" group. I may not get that good at the velocity I am looking for but I will have to see for myself.
The 44 grain loads had a nice crunch to them when loading! 44.5 is about as far as I am going to push it even though I didnt see any signs of overpressure.
Brings me to another question. What kind of pressure can a modern firearm handle? I am sure for liability gun makers and powder companies are well on the low side.

Personally I will push it right to the ragged edge but dont recommend ANYONE do what I do...ive blown primers out of the pockets with no ejection issues chasing loads...what ever you do just be careful and watch for pressure signs which will usually start with flat primers.

I have never tried to run one up like this. I just want to get to at least 2800fps to get my ballistics looking good. I dont see any difference in the brass at all right now between the 40 grain and the 44 grain. I guess its going to blow the primer before it doe any other damage?
I only have two more inches of barrel on the Creedmore and I am getting 2850 out of factory loads and reloads I made to emulate them. I was kinda hoping to get there, but I am finding out what the difference in the two cases is now. I should be able to load them a little longer and get by that issue. They are compressing starting at 43 just a little, and the 44 has a nice crunch, but I am still loading at 2.8 OAL. I am going to try and squeeze all I can out of it!

Like you said check your free bore and try seating the bullet out a little closer to the lands to help with the compressed load. Another thing is that barrel may just be a slow barrel and you may not be able to get the velocity your looking for with 4350 if not pick up a pound of RL-17 and give it a try.

I agree with LR.
Check your free bore.


I found R17 the champ of easy speed and it did not suck in the accuracy and ES/SD depts and keep a few #'s around if I run out of H4350.

Is the best way to do that without a 100 dollar tool to put a 140 on top of a resized brass pulled out really far and close the bolt on it?

A lot of guys do something like that but I think they cut the neck and use a black marker to paint the bullet so they can see where the bullet stopped pushing in to the case...im pretty sure someone will post up that does it that way.

Quote:

---

Originally Posted by LongRange

A lot of guys do something like that but I think they cut the neck and use a black marker to paint the bullet so they can see where the bullet stopped pushing in to the case...im pretty sure someone will post up that does it that way.

---

I use a cut case, set my bullet seater with it too.

I got the 260 running 2850 with 44.5 gr of IMR4350. I tried 45 also and still didnt get any pressure signs but 2850 looks pretty good to me! I didnt get the chrono on the 45's but the group didnt look great either. The 44.5 @ 2850 were under an inch and I think I will play with the seating to tune them in.
Thanks for all your help guys. My hunter is about ready to go!

2850 is a good number.